High-Flow Nasal Oxygen in the Adult Emergency Department Ammara Doolabh James Hughes Princess Alexandra Hospital Emergency Department

High-Flow Nasal Oxygen “High-flow”, “Airvo”, “Optiflow”, “HFNO” Widely used and studied in paediatric populations Recently introduced into adult populations Limited literature on use in adult populations Particularly ED Setting (single study on management of hypoxemic respiratory failure) Focus on hypoxemic respiratory failure

High-Flow Nasal Oxygen Able to generate flow dependent positive pressure within the upper airways Associated increase in end expiratory lung volumes Nasopharyngeal dead-space washout and oxygen reservoir Improvements in a number of clinical parameters (Oxygenation, HR, RR, dyspnoea scores, supra- clavicular recession, thoraco-abdominal asynchrony) Useful for both “stepping-up” and “stepping-down” respiratory support

HFNO in the ED Improvements as early as 15 minutes after commencement Better patient tolerance and adherence (compared to systems requiring a face-mask) Lower cost per use (compared to NIV) Acceptable usage for caregivers (set-up and management) within an ED setting

To explore the role of HFNO in an adult emergency department Objectives To explore the role of HFNO in an adult emergency department Indications for use Outcomes of use

Our Study Explorative, retrospective study Chart review Patients 18 years or older Received HFNO within the PA Hospital Emergency Department 2014 Calendar Year Ethical Approval from both Metro South Health and University of Queensland School of Medicine Human Research Ethics Committees

Results 39 patients identified Male patients: 29 (74.4%) Age range: 24-90 years Mean age: 60 years (SD 17.201)

Pre-HFNO Oxygenation

Indications for HFNO Use 35 patients with pre-HFNO blood gas values available Patients with normal blood gas analysis: “Step-up”: 3 “Step-down”: 1

Diagnoses

Influenza Status 18 Patients with Nasopharyngeal Swab and PCR Analysis for Influenza A and Influenza B

Clinical Effects of HFNO

Effects of HFNO on Carbon Dioxide Levels 16 patients with both pre-HFNO and post one hour of HFNO Blood Gas Analyses available 6 hypercapnic patients, 10 normocapnic patients

Cessation of HFNO and Post-HFNO Oxygenation HFNO Patients (n=39) Discharged to Ward on HFNO (n=27) HFNO Ceased in ED (n=12) Condition Improved (n=7) NRB (n= 1) NP (n=4) RA(n=2) Patient Refusal (n=1) HM (n=1) Unsatisfactory Progress(n=2) NRB(n=2) NIV Commenced (n=2) CPAP (n=1) BiPAP (n=1) HM = Hudson Mask, NRB = Non-Rebreather Mask, NP = Nasal Prongs, RA = Room Air

Limitations Small number of patients Retrospective nature of the study Missing data / data inconsistencies Lack of comparison or control arm Causal relationship cannot be established Results can be attributed to “regression-to-the-mean” or concurrent treatments Only focused on outcomes within the ED

Conclusion HFNO is useful for a number of indications within the PA ED Associated with improvements in a number of clinical parameters HFNO may be useful in the ED management of hypercapnic patients Questions for further research Role of HFNO in management of hypercapnia Outcomes of ED HFNO patients beyond the ED

Thank You